Hello Stephenw and thanks for your answer.
After a while of playing around I seem to have found the issue, it now disables the backlight when the lid closes, SUCCES! :D
I don't know which command actually did it, so I'll post them all:
vidcontrol -t 1 < /dev/console
vidcontrol -t 1 < /dev/ttyv0
vidcontrol -s 1 < /dev/ttyv0
So a combination of green_saver.ko module and one of the above commands helped me disable the backlight.
Thanks for your support,
Cheers
EDIT:
Or not … I just pushed on the screen and the backlight disabled itself, so either the commands are working as intented or the switches are somewhat broken...
I just put an heavy object on the screen and it's disabled, works anyway.